Create a structure-aware fuzzer (second try)

[addisoncrump]

This is a retry of #1902. Depends on #1954.

This PR adds two three experimental fuzzers which generate valid JavaScript code from Arbitrary structs. These fuzzers (or variants thereof) were used to identify all of my previous PRs and issues. It does not generate identifiers which resolve to built-in types.

I will link issues discovered by this fuzzer to this PR as they are discovered. As with last time, if you wish to test using this fuzzer, I would recommend using:

cargo fuzz run -s none interp_fuzzer -- -timeout=5

[codecov]

Codecov Report

Merging #2169 (376c953) into main (48d8b42) will decrease coverage by 1.98%.
The diff coverage is 1.57%.

❗ Current head 376c953 differs from pull request most recent head 6887bcb. Consider uploading reports for the commit 6887bcb to get more accurate results

@@            Coverage Diff             @@
##             main    #2169      +/-   ##
==========================================
- Coverage   42.04%   40.06%   -1.99%     
==========================================
  Files         231      233       +2     
  Lines       21271    22356    +1085     
==========================================
+ Hits         8943     8956      +13     
- Misses      12328    13400    +1072     

Impacted Files	Coverage Δ
boa_engine/src/context/mod.rs	30.83% <ø> (ø)
boa_engine/src/lib.rs	86.66% <ø> (ø)
boa_engine/src/syntax/ast/constant.rs	50.00% <ø> (ø)
boa_engine/src/syntax/ast/node/array/mod.rs	33.33% <ø> (ø)
boa_engine/src/syntax/ast/node/await_expr/mod.rs	28.57% <ø> (ø)
boa_engine/src/syntax/ast/node/block/mod.rs	50.00% <ø> (ø)
boa_engine/src/syntax/ast/node/call/mod.rs	69.23% <ø> (ø)
.../syntax/ast/node/conditional/conditional_op/mod.rs	64.28% <ø> (ø)
...x/ast/node/declaration/async_generator_decl/mod.rs	13.33% <0.00%> (ø)
...x/ast/node/declaration/async_generator_expr/mod.rs	5.55% <0.00%> (ø)
... and 59 more

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[addisoncrump]

Note that (as part of this PR) we should add build step check to CI for fuzz with cargo fuzz build. Not entirely sure how to do that, though.

[addisoncrump]

Added another fuzzer which checks for parser/interner idempotency. This should help find issues like #2148 and other tricky parser/interner bugs.

[addisoncrump]

Closing in favour of new techniques.